Alternating-current relay



L. H. PETER I Sept. 11, 1928. 1,683,696

ALTERNATING CURRENT RELAY Filed Feb. 18. 1928 2 Sheets-Sheet 1'INVENTOFC ,l ,H. Pet 6 r,

Sept. 11, 1928. 6 1,683,696

L. H. PETER ALTERNATING CURRENT RELAY Filed Feb. 18. 1928 2 Sheets-Sheet2 15 ulazfz'on Zazfion |NVENTORI X. .H Pea-C6 I,

ax-W HQ ATTORNEY Patented Sept. 11, 1923.

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LESLIE H. PETER, OF LONDON, ENGLAND, ASSIGEOR, MESHE ASSIGNMENTS, TO THE'UNIO1\T SWITCH & SIGNAL COMPANY, OF SVIIESSVALE, PENNSYLVANIA, ACORPORA- TION OF PENNSYLVANIA.

Application filed February 15:, 1928, Serial No: 2

This invention relates to alternating current relays oi the two elementinduction type in which the magnetic system of the relay comprises twodistinct sets of poles,

each of these sets comprising poles adapted to produce a torque upon thevane or movable element, the torque due to one set of poles beingarranged to be opposite to that due to the other set, with the object ofrendering the relay effectively responsive to alternating current of aparticular frequencysupplied to both windings or elements of the1'8li1), 2111l unresponsive to ill. ternating currents of a" difi'erentfrequency.

The principal feature of the present invention is the provision of animproved form of core structure tor-the magnetic system of the. relaywhereby the opposing torques exerted upon the movable element arearranged tojbe more exactly balanced torthe frequency at which. it isdesired that the relay shall be unresponsive, thus preventing anytendency of the movable element to creep towards its operative position.under these conditions.

According to the present invention this object is attained by, soconstructing the magnetic cores traversed by the corresponding fluxescausing the opposing torques, that these cores are physically andmagnetically separate from one another, but are surrounded by or linkedwith an energizing winding or windings common to both cores.

I will describe one form of relay embodying my invention, and willthenpointoutthe novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a view showing, in sideelevation, one form of relay embodying my invention. Fig. 2 is a topplan view o'f'a port-ion of the relay shown in Fig; 1 and is also adiagran'imatic view showing onev form of apparatus with which the relaymay be used. Fig. 3 is a.

sectional view along the line III-IH of 45 Fig. 2. Fig. 4 is a sectionalview along line IV--IV of Fig. 2.

Similar reference charactersrefer to siin-' ilar parts in each oftheseveral views. I Referring! now to the drawings it seen that themagnetic system of the designated in general by the reference actor Rcomprises two physically and char .rnagwill be rel ayALTERNATIHG-CURREHT RELAY.

55.4%. and. in Great Britain February 15, 192?.

netica'lly' separate cores 1, 2 each composed of the usual laminationsor stampings, each core being substantially Q-shaped and having atransverse air gap in oneof its sides,

the movable element 3 of the relay c0nsti-. tuted by a circular discbeing adaptedto move within bot-h such air gaps. The cores 1, 2- are somounted within the relaycasing i that-the plane of the laminations ofthe corefl is inclined at an angle of approximately to the plane of thelaminations.

of the core 2, the baclt leg 5 of theside of the rectangular core 1which is opposite to the side containing the air gap being closelyadjacent to the corresponding back leg 6 of the other core-2. The cores1, 2 are sup ported in this position by means of an angu lar bracket 7and the adjacent sides oi: both cores are surrounded by a commonwindingAs, best shown in Fig. 2, the'winding S made in two sections connectedinseries and each surrounding the bacln legs 5 and 6 of both the cores 1and 2. The opposing pole t'aces 10 and 11 of the core 1, and the polefaces 12 and 13 of core 2 formed atthe air gaps above referred. toare-slotted to accommodate a local winding 9 constitutedv by a copperstrap bent into a suitable form to surround the portions into which thepole face is divided by the slots formed therein. Referring now to Figs.2, 3, and 4, it will be seen that the winding 9 is in the form of aletter S on pole tacos lOand 12, whereasthis winding merelypassesthrough the pole faces 11 and 18.

i It will be observed that the cores 1,2and

the fluxes traversing these cores are magnettwo fluxes at thevpredetermined frequency in a simple and efiective manner. I The movableelement 3'0fthe relay is arranged to operate relay contacts in theusualv manner the mechanism connecting the movable" element 3 and thesecontacts being of any desired character.

The operation of the relay is as follows 2- The parts of the relay areso designed and of a different frequency, however, such for example as ahigher frequency, the torque exerted on the disc by the shiftingmagnetic field in the air gaps of one of the cores 1, 2 is arranged tobe greater than the torque exerted on this disc by the shifting magneticfield in the other air gaps, this being preferably'eifected by theprovision of short circuited conductors 12 and 13 surrounding theopposing pole faces ofcore 2. (See Figs. 2, 3 and 4:.) hen thecurrent ofthe higher frequency referred to above is supplied to the relaywindings, the short circuited conductors 12 and 13 reduce the amount offlux in pole faces 12 and 18, and increase the amount of flux in polefaces 1G and 11,-so that the torque exerted on the movable element 3 bythe shifting magnetic field produced by core 1 is greater than thetorque exerted on this element by the shift ing magnetic field producedby core 2. The disc is thus caused to rotate so that the relay contactsare closed.

Relays embodying my invention are suitablefor, though in no way limitedto, use in railway signaling systems, such, for example, as the systemillustrated diagrammatically in Fig. 2. Referring to this view, thereference characters 15 and 15 designate the track rails of a railway,which rails are divided, by means of insulated points 16, to form aninsulated track section AB.

" These rails are supplied with alternating propulsion current from agenerator G the terminals of which are connected with the rails throughbalanced bonds 27. The rails are provided, as usual, with bonds 26 toconduct the propulsion current around the inby wires 20 and 20. Winding8 of relay R is'al'so connected across the rails of the section AB bywires 17 and 18, and winding 9 is constantly supplied with alternatingcurrent from generator G through a transformer T,;the secondary of whichis connected with the winding9 and the primary of which is connectedwith wires 19 and 19 through the medium ofwires 21 and 21% As shown inFig. 1, the transformer T is located within the relay casing, but thisparticular arrangement ,is not essential. The contacts of relay'R may beutilized to control signaling apparatus not shown in the drawing in anysuitable manner.

The propulslon current. supplled by generator G and the signalingcurrent supplied by generator G differ in frequency; for example, thepropulsion cur rent frequency may be 25 cycles per second, and thesignaling current frequency may be 60 cycles per second. The relay R isso designed and proportioned. that when 60 cycle current'is supplied'toboth the windings 8 and 9, a torque is created on the movable element 3tending to shift this element and close the contacts of the relay. If,how

ever, current of the propulsion frequency should be supplied tobothwindings 8 and 9, due to any defect in the apparatus, the effect ofthis currentwould be to equalize the torques exerted on the movableelement 3 by the shifting magnetic fields produced by the cores 1 and 2so that the movable element would move to or remain in its normalposition in which the contacts of the relay would be open. 7

If desired, a condenser 30. or its equivalent may be associated with thetrack winding 8 of the relay as shown in Fig. 2, in order, to supply thewattlesscomponent of the current taken by this winding, the condenserbeing of such capacity that the circuit of the track winding 8 isresonant at the frequency at which it is desired that the relay'shouldbe responsive. In certain cases the condenser above referred to may havea greater capacity than is necessary to supply the wattless component ofthe current in the track winding 8 and the extra current taken by thecondenser may be made to neutralize the wattless component for the bondat the relay end of the block section.

The invention is not limited to the particular constructional form andrelative arrangement of the cores above described by way of example, andvariations in these and other respects may evidently be made withoutexceeding the scope of the invention.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is;:.'

1. A relay comprising two distinct mags netizable cores each terminatingin opposed pole faces to form an air gap, a first winding associatedwith both said cores and operating when supplied with current to createfluxes in both said cores, a second winding associated with said polefaces and adapted to receive energy from a source outside of the relay,and a movable element mounted to be oppositely affected by the fluxestraversing said air gaps.

2. A relay comprising two magnetizable C-shaped cores each terminatingin opposed pole faces to form an air gap and located in intersectingplanes but having their back legs in juxtaposition, a first windingsurwflux in said two air gaps due to current in each said winding varieswith variations in the frequency of the current supplied to the winding,and a movable-element mounted to be oppositely affected by the fluxestraversing said air gaps.

3. A relay comprising two magnetizable C-shaped cores each terminatingin opposed pole faces to form an air gap and located in intersectingplanes but having'their back legs in pixtaposition, a first windingsurrounding both said back legs, an element of electro-conductingmaterial interposed in both said air gaps and movable in a plane atright angles with the planes of both said cores, asecondwindingfassociated with said pole faces and arranged in suchmanner that when both said wmdmgs are supplied with alternating currentshlfting magnetlc fields are created in said two air gaps which tend tomove said element in opposite directions, and a contact controlled bysaid element.

4. A relay comprising two magnetizable C-shaped cores each terminatingin opposed pole faces to form an air gap and having their back legs injuxtaposition, two windings one surrounding both such back legs and theother associated with said pole faces in such manner that when thewindings are supplied with alternating currents diifering in phase ashifting magnetic field is created in each said air gap, shortcircuitedconductors associated with the pole facesvof one said core butnot the other whereby the dis tribution of flux in said two air gaps dueto current in each winding varies with Variations in the frequency ofthe current supplied to the winding, and a movable element mounted to beoppositely affected by the shifting magnetic field in said two air gaps;

In testimony whereof I afiix my signature.

LESLIE n. PETER.

